Within the field of graph preprocessing, a prominent class of methods involve partitioning the vertices to aid visualisation or computation. These methods come under the names of community detection [1]}, graph partitioning [2]} and graph clustering [3]}.
Preprocessing of graphs can also be viewed from the angle of data compression. Graph compression, just as clustering, is also based on grouping vertices, while storing additional information in order to recreate the original graph [4]}, [5]}, [6]}, [7]}, [8]}.
